1. Field of the Invention
The present invention relates to a disk cartridge to accommodate a disk that is an information recording/reproducing medium and more particularly, to a disk cartridge to protect a recording surface of the disk from a contaminant such as dust or finger prints.
2. Description of the Related Art
In general, a disk cartridge accommodates a disk that is an information recording/reproducing medium and is loaded into a disk drive apparatus. As shown in FIG. 1, a disk cartridge 100 includes a case 101 to accommodate a disk D, and a shutter 110 installed inside the case 101 to rotate and to selectively open and shut an opening hole 102 formed in the case 101 so that a pickup (not shown) of a disk drive apparatus may access the disk D. A cover 103 is also provided on the disk cartridge 100 to block an entrance of dust by sealing a disk accommodating space to prevent contamination of the disk D by dust. However, an effect of dust adhering to a recording surface of the disk D during signal processing is negligible because of recent developments in software. Thus, the cover 103 is frequently omitted.
When the disk cartridge 100 is loaded into the disk drive apparatus, as shown in FIG. 2A, an opening lever 120 installed in the disk drive apparatus first presses a locking piece 111a to unlock a protrusion 111c of the shutter 110 from a groove 101a of the case 101. Next, as shown in FIG. 2B, the opening lever 120 completely pushes an interference piece 111b to rotate the shutter 110. The shutter 110 includes first and second shutter portions 111 and 112 installed to rotate around each of left and right rotation shafts 110a, and engaged with each other via an engagement gear portion 113. Accordingly, as the first shutter portion 111 integrally connected to the interference piece 111b rotates clockwise, the second shutter portion 112 rotates counterclockwise, so that the first and second shutter portions 111 and 112 are separated widely, thus opening the opening hole 102. Then, a pickup (not shown) of the disk drive apparatus accesses the recording surface of the disk D through the opened opening hole 102 to perform recording and/or reproduction of information. Although not shown in the drawings, a torsion spring to elastically bias the first shutter portion 111 counterclockwise (that is, in a direction to close the opening hole 102) is installed at the rotation shaft 110a between the first shutter portion 111 and a bottom surface of the case 101. Thus, when a force pressing the opening lever 120 is removed, the shutter 110 returns to an original state before the opening hole 102 is opened.
However, in the above-described structure, since the shutter 110 is installed inside the case 101 and the disk D is placed on the shutter 110, during opening and shutting operations of the shutter 110, the recording surface of the disk D (e.g., a lower surface of the disk) and the shutter 110 make a surface contact which may damage (e.g., scratch) the disk recording surface. The scratch may be a more severe external interference factor compared to that of the dust adhering to the recording surface. Therefore, a structure which protects the recording surface of a disk during the opening and shutting operations of the shutter 110 is needed.